不锈钢薄板储能焊点焊接头的显微组织与力学性能

Microstructure and Mechanical Properties of Capacitor Spot Welding Joint of Stainless Steel Sheet

对0Cr18Ni9奥氏体不锈钢0.4 mm薄板进行了储能点焊试验,对其接头的显微组织和力学性能进行了分析研究。结果表明:焊接接头由熔核区、热影响区和熔核区向热影响区过渡的熔合区组成;熔核区显微组织由等轴奥氏体组成,由于储能焊极短的焊接时间和大的冷却速率,使熔核区的组织显著细化且具有快速凝固特征,其它区域组织与母材相当;当焊接电压为160 V、电极压力为18 N时,可获得有较高力学性能的焊接接头,其显微硬度为235.32 HV、抗剪强度为156.8 MPa。

The capacitor spot welding of 0Cr18Ni9 austenitic stainless steel sheets in 0. 4 mm thickness was carried out. The microstructure and mechanical properties were investigated. The results show that the welding joint was composed of the nucleus, the heat-affected zone（HAZ） and the fusion zone between melt nucleus and HAZ. There were equiaxed austenite in the nucleus. As a result of short weld period in the capacitor discharge welding and high cooling rate of the nucleus, the rest microstrueture was similar as the matrix, the grains were dramatically refined and had a characteristic of rapid solidification. The joint with high mechanical properties, whose microhardness was 235. 32 HV and the shear strength was 156. 8 MPa, could be obtained as the welding voltage U was 160 V and the electrode press force F was 18 N.